1. Field of the Invention
The present invention relates to artificial hair which is made of a polyamino acid, which has a degree of polymerization of about 50-10,000 and which, moreover, has pendant mercapto or disulfide groups.
2. Description of the Background
Of the many inevitable consequences of human aging, hair thinning or hair loss is, perhaps, one of the most apparent. While many adults adjust to life having less or no hair, others resort to wearing wigs in order to restore a sense of self-confidence and to be able to participate fully in society.
While hair thinning and hair loss is, perhaps, more characteristic of the male response to aging, an enormous market exists for hair wigs for women, who habitually wear wigs as a matter of fashion as the time, place and occasion require.
Thus, due to both cosmetic and psychological reasons, the hair wig industry for both men and women has grown rapidly in recent years, particularly so for men's hair wigs.
To date, human hair has been widely used in the construction of wigs. However, several difficulties are presented with the use human hair.
First, at present, women's hair styles have changed and as a result, women's hair is now worn fashionably short. Moreover, women's hair is often worn permed, such that it is no longer adequate to merely us straight long human hair in wig construction.
Secondly, in order to use human hair in wig construction, the hair must be subjected to many treatment steps starting with the removal of cuticles covering the surface of the hair. Additionally, other treatments are needed as well as sterilization, decoloration, coloring, and lustering, all of which tend to change the hair.
Thirdly, due to the uneven length and size of human hair, it is difficult to mechanize the setting of human hair on a wig base, and each hair must be set thereon by hand. Accordingly, enormous costs and much time are required in wig production. The inability to readily mechanize this process is, perhaps, the most relevant factor in wig expense and, moreover, tends to discourage wig use.
For the above reasons, synthetic fibers of the acryl type have been proposed as materials for wigs instead of human hair and to some extent these synthetic fibers have been used. However, these synthetic fibers exhibit the following disadvantages:
(1) The synthetic fibers are fused by heat so that special techniques and devices are required for styling and maintenance of hair wigs or hair pieces.
(2) The synthetic fibers have poor heat resistance so that if a person who wears a wig uses a hair drier carelessly, the wigs might become unusuable.
(3) The synthetic fibers fail to realize and maintain styling by gentle oxidation-reduction treatment (cold perm), as is possible with human hair.
(4) On the other hand, it is difficult for the wearer to change styling depending upon mood and, moreover, such wigs produce an unnatural feeling.
(5) Polyvinylidene chloride and a polyacrylonitrile are both quite dissimilar to the proteins which constitute human hair, such that the luster and touch of wigs made from such synthetic fibers are different from wigs made of human hair. Further, an image of wearing artificial hair is stroingly attached to the wearer and is perceived by those around him.
Hence, a need clearly continues to exist for a material which can be used in the construction of human wigs, which has the look and feel of human hair and which also is capable of being easily styled and maintained.